Sterile infusion fluid is used in various medical applications, particularly in blood-cleansing applications such as hemodialysis, hemofiltration, hemodiafiltration, or peritoneal dialysis treatments. In hemodialysis, for example, the infusion fluid is generally used to prime an extracorporeal circuit of a blood-cleansing machine, prior to connecting a patient to the machine, and to rinse back the patient's blood at the end of the treatment. Sterile fluid may also be administered to patients in the form of a bolus, which may improve the patient's fluid status, blood pressure, etc. In tile practice of hemodiafiltration, plasma water is removed by filtration from the blood as it traverses through the hemodialyzer cartridge and certain toxins or other material diffuses from the patient's blood. To compensate for this loss of plasma water, sterile fluid must be added either upstream or downstream of the hemodialyzer cartridge. The sterile fluid used in these applications is generally a normal saline solution (e.g., a solution having a sodium chloride concentration of 0.9 percent by weight) which is supplied pre-sterilized in one or two liter flexible bags. In some cases a Ringer's Lactate Solution might be used. In peritoneal dialysis, sterile dialysate packaged in flexible bags is typically infused into and subsequently emptied from the patient's peritoneal cavity.
In dialysis clinics that have multiple dialysis stations, the clinic must purchase and store large volumes of sterile fluid. The costs involved in buying and storing the pre-packaged sterile fluid may be significant. Further, peritoneal dialysis patients are typically treated at home and thus, the cost and storage capacity for the required amounts of sterile fluid, as much as 12 liters per day, become even more significant.